We wish to use Hitachi Chemical‘s micro RFID tag, laser-soldered to our jewelry instead of the conventional method of tagging with RFID using a thread or stickers. Would we be able to read the tags within a door frame measuring 5 feet by 6 feet, with an accuracy of 100 percent?
Hitachi Chemical’s passive ultrahigh-frequency (UHF) RFID tag measures about 2.5 millimeters (0.1 inch) square and 0.3 millimeters (0.01 inch) thick. By itself, the tag has a read range of about 10 millimeters (0.4 inch), due to the fact that the antenna is about the size of the chip. Hitachi says the range can be increased to as much as 4 meters (13.1 feet) if the antenna is coupled with a metal component on which the chip is mounted. I do not know what the read range would be if you mounted the tag on a gold or silver ring. You would need to purchase some chips and perform some testing to determine if you could interrogate the tags from the distance required.
—Mark Roberti, Founder and Editor, RFID Journal
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